1. Field of the Invention
The present invention relates generally to vehicles and, more particularly to, a method and apparatus for vehicle alignment.
2. Description of the Related Art
A vehicle such as an automotive vehicle must be aligned for proper handling of the vehicle and tire wear. The alignment parameters which are measured and adjusted include camber, caster and toe. Camber is defined as the angle which the wheel makes with respect to a vertical plane when looking at the wheel from either the front or rear of the vehicle. Caster is defined as the angle between the centerline of a typical steering knuckle and a vertical plane when looking at the wheel from the side of the vehicle. Toe is defined as the lateral distance between front edges of two wheels supported at opposite ends of a common axle and the rear edges of the wheels.
For proper vehicle alignment, camber, caster and toe need to be measured and adjusted throughout the suspension travel. Typically, the suspension travels through at least three suspension positions corresponding to design, jounce and rebound. Design position is defined as the distance between ground and bottom of the vehicle frame (e.g., a specified design position may be the distance when there is two passengers in the vehicle, a load in a trunk of the vehicle and a full tank of fuel in the fuel tank). Jounce position is defined as the distance between the wheel moved upwardly and the design position. Rebound position is defined as the distance between the wheel moved downwardly and the design position.
Conventionally, camber, caster and toe are adjusted at different work stations and at a single random height. Typically, a machine is required at each work station to perform the adjustments. As a result, there is no consistency in the vehicle alignment adjustments or settings from vehicle to vehicle. Further, these alignment parameters are not checked at its specified engineering design height before leaving the manufacturing plant. Therefore, a need exists in the art to adjust camber, caster and toe at one work station and for multiple suspension positions. Thus, a need exists to improve consistency in the vehicle alignment adjustments or settings from vehicle to vehicle before leaving the manufacturing plant.